Microsoft 365 Copilot vs ChatGPT for business: which should your team use?

If your business already runs on Microsoft 365, start with Microsoft 365 Copilot: it works inside Outlook, Teams, Word and Excel, with your own emails and files, under the Microsoft terms you already have. ChatGPT Business is a good choice when you want a standalone assistant, or your work is spread across tools beyond Microsoft. Whichever you choose, use the business edition, never the free or personal one, for client data.

What each one is

Microsoft 365 Copilot is Microsoft’s AI assistant built into the Microsoft 365 apps. The paid version is a per-user add-on that can work with the emails, files, meetings and chats each person already has access to. Every eligible Microsoft 365 business plan also includes the free Copilot Chat, which is secure but works mainly from the web and whatever you give it. Microsoft has recently started calling these Microsoft Copilot and Microsoft Copilot Chat, so you’ll see both names for a while. Our glossary entry has a plain-English summary.

ChatGPT is OpenAI’s assistant, used in its own app on the web, desktop and phone. Its business editions are ChatGPT Business, for teams of two or more, and ChatGPT Enterprise for larger organisations. ChatGPT Business can connect to Microsoft 365 and other tools such as Google Drive and Slack.

Why the free and personal versions are the wrong choice

The consumer versions of both are built for individuals, not for client data:

• ChatGPT Free, Go, Plus and Pro: OpenAI says conversations on these plans can be used to train its models unless each person turns off a setting called “Improve the model for everyone”. That leaves your client confidentiality depending on every member of staff having changed one setting.
• Copilot with a personal Microsoft account: Microsoft’s enterprise data protection applies when people sign in with their work account. Someone using Copilot on a personal account is outside your firm’s controls.

If staff are already using personal AI accounts for work, that’s worth tackling now. Pick a business tool, write a short policy on what can and can’t go into it, and tell people. We never use consumer chatbots with client data, and we’d advise the same for any firm.

Inside Microsoft 365, or a separate app

This is the biggest practical difference. Copilot is where the work already is: summarising a long thread in Outlook, drafting a letter in Word from your own documents, or asking what was agreed in a Teams meeting. With the paid licence it searches across what each person can already see, and it respects your existing permissions. That’s a strength, but it also means a folder shared too widely becomes visible in Copilot’s answers, so tidy permissions first. Our post on getting real work out of Copilot covers that groundwork.

ChatGPT is somewhere you go. You paste text in, upload a file, or connect apps, including Microsoft 365. OpenAI says admins choose which apps are available, each person signs in to a connected app themselves, and existing permissions are respected. It works well, but it’s another supplier to check, another admin console and another set of accounts to manage.

How each handles your data

One detail on Copilot: when it searches the web, a short search query goes to Bing, which runs under separate Microsoft terms. Your IT provider can turn web search off if that matters to you. For ChatGPT Business, make sure someone actually signs the processing agreement. Our glossary explains what a data processing agreement covers.

Where each is stronger for small-business jobs

In our experience, Copilot is the better fit for:

• catching up on email and drafting replies in Outlook
• recaps and actions from Teams meetings
• first drafts in Word based on your own files
• pulling together what the firm already knows about a client or project

People often reach for ChatGPT for:

• open-ended drafting, redrafting and thinking a problem through
• in-depth research reports on a topic
• analysing a spreadsheet or document someone uploads
• teams that also work in Google Workspace, Slack or other non-Microsoft tools

Neither one runs a whole process on its own, such as reading every email that arrives at info@, sorting it and drafting a reply. That’s automation. And if what you really want is staff asking questions of your own handbook and procedures, a company knowledge assistant is often a better fit than either.

What it costs

Both are priced per user per month. At the time of writing, Microsoft’s UK site lists Microsoft 365 Copilot Business, for organisations of up to 300 users, from £16.10 per user a month plus VAT on an annual plan, with a lower introductory price for the first year on orders placed before the end of 2026. It’s an add-on to a Microsoft 365 Business plan, and Microsoft also sells Business Standard and Business Premium with Copilot built in. OpenAI’s UK pricing page lists ChatGPT Business at £15 per user a month billed annually, or £18 billed monthly. Copilot Chat costs nothing extra.

The bigger cost is usually time: training people, tidying permissions and finding the uses that save real hours. Prices also change, so check before you buy.

A simple decision guide

• You run on Microsoft 365 and most work is email, documents and meetings: give everyone Copilot Chat, then trial paid Copilot with the people who’d use it most.
• Your work spans lots of non-Microsoft tools, or you want a standalone assistant: consider ChatGPT Business, with the processing agreement signed and the connected apps agreed.
• You’re tempted to buy both for everyone: don’t, at least at first. Some firms do use both, for different people. Start with one and add the other where there’s a clear reason.
• Staff are already using personal accounts: decide this month. A business tool plus a short safe-use policy beats a ban nobody follows.

Who does what

For businesses whose IT is looked after by Alphabyte IT, the work is split. Alphabyte IT handles the licensing and switches Copilot and the Microsoft 365 AI features on safely. AlphaOps focuses on getting real work out of Copilot and other AI tools, and on building automations. For the automations we build ourselves, we use Anthropic’s Claude through its business service, which doesn’t train on customer data and is covered by a data processing agreement.

Not sure which tool fits your team? Our free automation audit looks at how your business works and where AI would genuinely help. On our Monthly AI Support plans, we also keep track of new Copilot features as they arrive and set up the ones worth having, with your OK.